Chemical Forums
Chemistry Forums for Students => Organic Chemistry Forum => Organic Spectroscopy => Topic started by: Alucard on October 03, 2016, 02:48:01 PM
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Hello, I have been trying to figure out what unknown I have based on some tests I ran in class such as solubility, melting point, pH and physical characteristics. But I can not figure out what it is. So far I think it is phenol with some other functional group attached but I cannot figure out what. I could not run an elemental analysis because my solution turned black after I did the sodium fusion and my teacher just said skip it. Can I get any help please?
This is the data I collected such as solubility, melting point, pH and physical characteristics
(https://s11.postimg.org/cf3qadelr/IMG_20161003_112951947.jpg) (https://postimg.org/image/cf3qadelr/)
This is my Carbon and Hydrogen NMR
(https://s11.postimg.org/99j4k5vzj/IMG_20161003_113033363.jpg) (https://postimg.org/image/99j4k5vzj/)
This is my IR
(https://s11.postimg.org/plt69wab3/IMG_20161003_113122959.jpg) (https://postimg.org/image/plt69wab3/)
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It is a forum rule that you must show your attempt before we can help you. Why do you think it is a phenol? What data point to the existence of a second functional group?
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The reason I think it is phenol plus one more existing function group. My melting point was 34 to 41 Celsius and phenol's melting point is 42C. My IR indicates a alcohol group. I have two high range doublets, which, are in the H NMR range for aromatic benzene rings. I also have a short fat H NMR peak indicating a alcohol functional group. I have 4 unique carbons. All four of my unique carbons fall in the range, 110 - 160, which is the range for benzene carbons. I suspect I have a methoxy group para to my alcohol group. That would address my two doublets. That would also address my four unique carbons. However, I run into a problem. We have not learned how to name a benzene ring that was an alcohol group para to a methoxy group thus I have no way of looking up the molecule so that i can compare it to my physical characteristics.
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There are some problems positing a methoxy group. One is that the hydrogens and carbon of CH3O- should also show up in the NMR spectra. I tend to agree that there are two groups and that they have a 1,4 (para) relationship with each other. Can you think of any other substituents besides methoxy?
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Well some other groups I know are. The halogens, NH2 and NO2. I do not know how to name the last two as substituents. I know of other substituents but it can not be the others that I know about because they all of carbon and I only have four unique carbons.
Edit. I just looked up the possibilty of it being 4-Aminophenol or 4-Nitrophenol but the melting point was way off for both so now I am at a dead end again.
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NO2 is the nitro group. You can also use the chemical shifts to make some headway. Groups such as -OH shift the neighboring (ortho to the -OH) C-H group upfield.